Fire crews responded Monday afternoon to a vegetation fire that broke out in an area southwest of Mount Diablo, officials said. It was unclear initially exactly where the fire began and whether any homes or commercial buildings were threatened. Fire crews from the Contra Costa Fire Protection District and Cal Fire had been called to the blaze.

Rodeo Fire initially started 12:06 p.m. June 23 in Contra Costa County, California. After being active for 18 hours, it has burned 65 acres. By Tuesday morning, the fire has been fully contained. The cause of it remains under investigation.

Crews are battling a brush fire in Contra Costa County on Monday, CAL FIRE said.The fire started around 12:06 p.m. southeast of Clayes Court and Stirling Drive in Rodeo, and burned at least 62 acres.It's burning near Highway 4 and the Phillips 66 refinery.